To ensure a high yield in a process of manufacturing semiconductors or the like, it is important to early find defects occurring in process and take corresponding measures. With miniaturization of semiconductors in recent years, the effect of a fine defect on the yield cannot be ignored and defects to be observed have diversified accordingly.
A scanning electron microscope (SEM) type defect observation apparatus is an apparatus that is adapted to observe such various defects. In general, the SEM type defect observation apparatus observes a defect on the basis of the position of the defect detected by an upstream-side inspection apparatus. However, the miniaturization of semiconductors has increased the number of cases in which the upstream-side inspection apparatus cannot detect a defect. Thus, it is important more and more to enhance a fixed-point observation function which is used to set a location and range to be observed in the SEM type observation apparatus for observation of defects.
In addition, for a fixed-point observation, especially, for process monitoring in a process of manufacturing semiconductors, a length measurement SEM has been used. The length measurement SEM measures the length of a specified pattern, treats the measured length as a management value, and quantifies the degree of completion of the process. However, when a variation in the pattern whose length is to be measured is excessively large, the length measurement SEM is susceptible to extremely large process variations, such as an open line pattern, a shorted line pattern, and the like.
In addition, users' evaluation indicators have diversified. As a result, adequate evaluation cannot be performed only with measurement values in some cases. Along with such a trend, it has strongly been requested that a degree of completion of the process should be quantified with the use of various evaluation indicators by using the fixed-point observation function of the SEM type defect observation apparatus.
Patent Document 1 discloses a method for appropriately using a plurality of pattern edge detection algorithms according to patterns to be evaluated and thereby improving the accuracy in length measurement.
In addition, Patent Document 2 discloses a defect inspection apparatus that displays on a screen an image of a defect, calculated contrast and a luminescence distribution side-by-side, so that a user can select an optimal test condition with ease.
In addition, Patent Document 3 discloses a defect inspection apparatus that displays a list of images for each of setting conditions and a list of evaluation indicators on a screen so as to support a user in selecting an optimal condition.